String is a value coming from a database record in its cleanest form: String: ? < > ' - " `´& % ‰ € ® 2011
For use in a text form, especially the double quotes, must be encoded so the value="" doesn't break. We use htmlspecialchars (ENT_COMPAT) function. ENT COMPAT only forces double quotes to be changed into " (besides < > ? &)